JPS60208671A - Adjusting valve - Google Patents

Abstract

PURPOSE:To adjust either of the whole length of a flow passage or the sectional area of the flow passage by forming the fluid flow passage so that the flow passage becomes longer than the whole length of the fluid passing part and adjusting an inner valve engaged with the flow passage. CONSTITUTION:The screw at the part corresponding to the whole length L of the fluid passing part of the body is formed into a tapered form at a prescribed angle (alpha) so as to be made thinner towards a valve seat 4, and the outer peripheral edge of the convex spiral 11 of an inner valve 2 is closely engaged with the inner peripheral wall of the spiral groove 3 of the valve body 1 when the valve is perfectly closed, and the fluid passage for the fluid is not formed when the valve is perfectly closed. When the inner valve 2 is shifted from this state, a gap is formed between the convex spiral 11 and the spiral groove 3, since the spiral is formed into tapered form thinner towards the top edge, and a spiral-shaped fluid passage 8 is formed. The whole length of said spiral flow passage becomes shorter, as the inner valve 2 shifts to a valve rod 5 side.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a regulating valve, and particularly to a regulating valve that is effective for high-pressure fluid.

Recently, as plants become more efficient, the fluids they handle tend to become more pressurized. Looking at this in thermal power plants, high-pressure steam is being actively promoted in order to improve plant efficiency, including power generation efficiency.

Originally, regulating valves used in boilers for thermal power plants handle high-pressure fluids, so they suffer from internal valve wear, vibration, and noise. Various improvements have been made to the shape of the regulating valves, and the valves have been made multistage. However, to date, no valve has been developed that can reliably solve these problems. Rather, it can be said that the problem has become more serious as the pressure of steam has increased as mentioned above. In addition to this, large-capacity thermal power plants are also beginning to operate with intermediate loads depending on power demand, resulting in large boiler load fluctuations and an increase in the number of startups and shutdowns. The reality is that the life of the valve is also decreasing accordingly.

This invention was constructed in view of the above-mentioned problems,
It is an object of the present invention to provide a regulating valve that causes less vibration, noise, and wear of the valve, and is capable of regulating a higher differential pressure than conventional ones.

In short, this invention forms a fluid flow path so that the flow path is longer than the entire length of the fluid passage, and adjusts the total length of the fluid flow path and the cross-sectional area of the flow path by adjusting the inner valve that engages with the fluid flow path. The valve device is configured such that at least one of the two is adjustable.

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show cross sections of the regulating valve, with FIGS. 1 and 1 showing the fully closed state, and FIG. 2 showing the fully open state.

Reference numeral 1 in the figure indicates a valve body, and a spiral groove 3 is formed in the valve body 1, which serves both as a fluid flow path and as a guide for an inner valve. For one-way valve 2, a convex spiral 1 engages with this spiral groove.
1 is required, for the purpose of reducing rotational torque, a plurality of notches are provided as shown in FIG. Move in the axial direction. The tip end (lower end in the illustrated valve arrangement) of the inner valve 2 is a valve body part 13 that tightly engages with the valve seat 4 of the valve body 1. Reference numeral 5 designates a valve body, and a plurality of protrusions 6 are formed in the longitudinal direction of the side of the valve body, and the valve body has a so-called spline connection and engages with a groove 14 formed in the insertion hole 7 of the inner valve 2, as shown in FIG. , see FIG. 4), the inner valve 2 is rotated and the protrusion 6 and the groove 14 slide, thereby allowing the inner valve 2 to move in the axial direction of the valve body l. be. In addition, several threads of the convex spiral on the valve stem 5 side of the inner valve 2, that is, the upper part in FIG. . Note that it is preferable to provide a small-diameter balance passage 2a for discharging fluid that has leaked into the space 15a between the upper lid and the main body. Reference numeral 15 denotes an upper lid, which is connected to the valve body 1 by a removable means such as a bolt, and the aforementioned valve stem 5 is inserted through the upper lid 15, and is rotated by a handle or the like (not shown). It's Nishide.

The operation of the regulating valve having the above configuration will be explained using an example in which the inner valve 2 is opened to allow fluid to pass from the fully closed state shown in FIG. 1. First, by rotating the valve stem 5, the inner valve 2 moves toward the valve stem 5 (in the illustrated case, rises) due to the engagement of the convex spiral 11 with the spiral groove 3 of the valve body 1. As a result, the close contact between the valve body portion 13 and the valve seat 4 is released. In the case shown in the figure, the spiral of the part corresponding to the entire length of the fluid passage part of the main body is tapered at a predetermined angle α so as to taper toward the valve seat 4, and the inner valve 2 is convex when fully closed. Shape screw #! Since the outer circumferential edge of the valve body 1 is configured to tightly engage with the inner circumferential wall of the spiral groove 3 of the valve body 1, no fluid flow path is formed when the valve body is fully closed. When the inner valve 2 is moved from this state, since the spiral is formed into a tapered shape, a gap is formed between the convex spiral 11 and the spiral groove 3, and a spiral fluid flow path 18 is formed. . As the inner valve 2 moves toward the valve body 5, the flow path 1B increases the gap between the inner diameter of the spiral groove 3 and the convex spiral 11, that is, the cross-sectional area of the flow path, and is constituted by both 3 and 11. The total length of the spiral flow path becomes shorter. In other words, by moving the inner valve 2, the fluid flow path 18 can be formed, the cross-sectional area of the flow path 18 can be increased or decreased, and the total length of the flow path can be increased or decreased. By adjusting, the flow rate and the differential pressure between the inlet 17 and the outlet 16 are adjusted to a predetermined value.

FIG. 5 schematically shows the relationship between the total length of the flow path and the average cross section of the flow path. The shaded area in the figure indicates the average cross-sectional area of each flow path, and this cross-sectional area is proportional to the average gap W1 to WJ between the outer peripheral edge of the convex spiral 11 and the inner peripheral wall of the spiral groove 3. In the case shown, the total length of the flow path is 2. ) J, > too)! , ) J,
, the gap corresponding to each total length is W□<W2<
The relationship W3<WJ<W5 holds true.

In the above case, when the valve is fully closed, the outer peripheral edge of the convex spiral 11 of the inner valve 2'' and the inner peripheral wall of the spiral groove 3 are configured to tightly engage with each other, and no fluid flow path is formed. However, when the valve is fully closed, a gap is formed between the two to form a spiral flow path in advance, and the valve is closed by the close contact between the valve body part 13 and the valve seat 4. You can leave it there. When formed in this manner, the change in the cross-sectional area of the flow path increases by the amount of the gap formed in advance.

Furthermore, the formation of the tapered portion itself may be abolished, and a gap may be formed between the outer circumferential edge of the convex spiral 11 and the inner circumferential wall of the helical groove 3 to form a helical flow path in advance. In this case, the opening/closing of the valve and the flow rate adjustment are all performed by the valve body 13 and the valve seat 4.
The fluid flowing into the valve body is depressurized by passing through the spiral flow path. In this case, the cross-sectional area of the flow path cannot be changed, but the spiral portion can be easily worked.

By carrying out this invention, it is possible to form an extremely long flow path with respect to the entire length of the valve body, so that the valve body can be made smaller and even high-pressure fluid can be significantly reduced in pressure.

Further, valves generally undergo increased wear during minute adjustments, but in the case of the present invention, minute adjustments are made using a long flow path, so wear can be significantly reduced and the life of the valve can be extended.

Furthermore, since the fluid itself flows smoothly even when the valve is throttled, it generates less vibration and noise.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views of a regulating valve according to an embodiment of the present invention, with FIG. 1 showing the fully closed state and FIG. 2 showing the fully open state, respectively.
Figure 3 is a sectional view taken along line A-A in Figure 1, and Figure 4 is a cross-sectional view taken along line A-A in Figure 1.
FIG. 5, a cross-sectional view taken along line B, is a diagram showing the relationship between the total length of the flow path and the average cross-sectional area. 1... Valve body 2... Inner valve 3... Spiral groove 11... Convex spiral 16... Fluid outlet 17... ...Fluid inlet 18...Fluid flow path L...Fluid passage section total length J, , J-2, JJ, J,, J-,...
・Fluid flow path length Fig. 1 1j Fig. 2

Claims (1)

[Claims] 16. A fluid flow path is formed in the valve body so that the flow path is longer than the length of the fluid passage portion of the main body, and an inner valve is engaged with this fluid flow path, and the inner valve is adjusted. A regulating valve characterized in that the length and/or cross-sectional area of the fluid flow path is made variable. 2. The regulating valve according to claim 1, wherein the fluid flow path of the valve body is formed in a spiral shape, and the convex spiral of the inner valve is configured to engage with the spiral portion. . 3. At least a portion of the spiral portion from the fluid inlet side to the fluid outlet side is formed so as to become wider toward the fluid outlet side, and the diameter of the convex spiral portion of the inner valve is also set at the tip thereof. 3. The regulating valve according to claim 2, wherein the regulating valve is formed so as to gradually increase from the side, and the cross-sectional area of the fluid flow path is changed by rotation of the inner valve. 4. The regulating valve according to any one of claims 1 to 3 of the patent, characterized in that the inner valve and the valve stem are spline-connected. 5. Claims 1 to 5, characterized in that the tip of the inner valve is formed into a spindle shape, and the valve seat is configured to change the fluid passage cross-sectional area and completely close the valve. The regulating valve according to any of paragraph 4. 6. The regulating valve according to any one of claims 1 to 5, wherein the convex spiral of the inner valve is cut out at a plurality of locations up to the vicinity of the base of the spiral. 7. Claim 1, characterized in that the plurality of threads on the valve operating handle side of the convex spiral of the inner valve are formed without a taper.
The regulating valve according to any one of Items 6 to 6. 8. The outer diameter of the convex spiral of the circular seat is formed to be smaller than the bottom diameter of the spiral groove on the valve body side at any operating position of the inner valve, and the main flow is carried out at the valve seat. A regulating valve according to any one of claims 1 to 7. 9. The regulating valve according to any one of claims 1 to 3, wherein the valve body spiral portion, the inner valve spiral portion, and the valve seat are formed of a wear-resistant material.